Recently, according to the increased demand of a video camera for use in the home, it has been required that the video camera be smaller in size and lighter in weight. Therefore, as a pickup device of a video camera, a conventional pickup tube has been changed to a solid state image sensing device. In a charge coupled device or metal oxide semiconductor type solid state image sensing device in which high density semiconductor technolgy is adopted, the tendency of color conversion is accelerated and the resolution is rapidly enhanced according to the progress of high density technology in the semiconductor field.
A color solid state image sensing device has been embodied by adopting a color filter on the photocell array region in the form of a matrix. The color filter has at least three coloring pattern groups, each having color resolution characteristics different from one another. In the case of a combination of three primary colors, the color filter has red, blue and green coloring pattern groups, and in the case of a combination of complementary colors, it has cyan, yellow and magenta coloring pattern groups. Accordingly, to manufacture the color filter on the photocell array region of the solid state image sensing device, processes of coating photosensitive resins, exposure, development, dyeing and color mixture prevention should be carried out at least three times. Accordingly, the color filter has a structure in which a plurality of layers are laminated so that it becomes very thick. Therefore, in such a thick color filter the quantity of transmitted light eventually arriving at the photocell array is decreased, thereby lowering the sensitivity of the solid state image sensing device.
To solve the problem of the decrease of light transmittance due to the thickness of the color filter, Japanese patent laid-open publication No. 61-199659 discloses a technique for enhancing the sensitivity by focusing the light onto each photocell after forming the condenser lens array on a surface of the color filter to be overlapped with the photocell array. However, this system is very complicated in its structure.